Certain dynamic software languages, such as JavaScript® , may be viewed as implementing hashtable functionality at their core. In computer science, a hashtable or hash map is a data structure that uses a hash function to map identifying values, known as keys (e.g., a person's name), to their associated values (e.g., their telephone number). Thus, a hashtable implements an associative array. The hash function is used to transform the key into the index (the hash) of an array element (or memory location) where the corresponding value is to be sought.